In March 2012, the United Nations made an important announcement: ‘The goal of reducing by half the number of people without access to safe drinking water has been achieved’ (United Nations 2012). While major news organizations heralded the achievement, this may be another premature claim of ‘mission accomplished’. This is because the way progress is measured on the Millennium Development Goals (MDG) water target does not fully address water quality, quantity and access – key components of the target that are fundamental to human health.

Target 7c of the MDGs calls for ‘reducing by half the portion of people without sustainable access to safe drinking water’ (UN 2000). Unfortunately, there is no clear guidance on precisely what was intended by the language of the target or definitions of the key terms ‘sustainable’, ‘access’ or ‘safe’. However, the language used in the target has a history and that history provides insights into its intent. The 1977 Mar del Plata Declaration by the United Nations, which launched the Water and Sanitation Decade (1981–1990), asserted the universal right to ‘access to drinking water in quantities and of a quality equal to their basic needs’ (UN 1977). Agenda 21, the UN action plan for sustainable development that emerged from the United Nations Conference on Environment and Development, expressed its goal in terms of ‘safe water’ and set a minimum quantity of 20 l/person/day (WSSCC 2000). Finally, the Secretary General’s report to Millennium Summit urged the adoption of a target to reduce by half the portion of people who lack ‘sustainable access to adequate sources of affordable and safe water’ (Annan 2000).

After adoption of the MDGs, the UN Millennium Project was commissioned to identify the best strategies for meeting the goals. In its report, the Millennium Project’s Task Force for Water and Sanitation defines ‘safe drinking water’ as ‘water that is safe to drink and available in sufficient quantities for hygienic purposes’ (UN Millennium Project 2005). The Task Force also explained that ‘access to drinking water requires the existence of infrastructure in good working order.’ It also noted that sustainable access implies ‘a type of service that is secure, reliable, and available for use on demand by users on a long-term basis.’

From this prior history, a few conclusions can be drawn about the intent of the MDG water target. First, with respect to quality, the intent is absolutely clear: drinking water must be ‘safe’. In opting for this criterion over ‘acceptable’, ‘acceptable quality’ or ‘quality equal to their basic needs’, the MDG target establishes an unequivocal mandate that water be free of pathogens. By focusing on ‘drinking water’ rather than water ‘sources’, the target also implies that the water be safe at the point of use, not just at the point of distribution. Second, like most of the previous statements, the MDG expressly includes the concept of ‘access’. The MDG Task Force on Water and Sanitation interprets this to include not only time spent procuring water – the traditional measure of access – but also in terms of (i) affordability, (ii) reliability and (iii) the environmental impact of the supply (UN Millennium Project 2005). However, access also implies quantity, as the inverse relationship between distance to water supplies and the amount of water used has been consistently shown for more than 40 years (White et al. 1972).

Each of these priorities – quality, quantity and access – has been shown by research to be fundamental to optimising health and development. Systematic reviews of dozens of field studies have shown that interventions to improve water quality are effective in preventing diarrhoeal diseases – a leading killer of children (Esrey et al. 1991; Fewtrell et al. 2005; Clasen et al. 2006; Waddington et al. 2009). Field studies have consistently shown that in the absence of safe storage, even water that is safe at the point of distribution is subject to frequent and extensive contamination during collection, transport, storage and use in the home (Wright et al. 2004). Systematic reviews have shown that interventions to improve quantity and access are also effective against waterborne diseases such as diarrhoea (Esrey et al. 1991; Fewtrell et al. 2005; Waddington et al. 2009). Moreover, by increasing water for personal hygiene, such interventions can also be protective against respiratory infections, trachoma and skin infections (Esrey et al. 1991; Rabie & Curtis 2006; Ejemot et al. 2008). A recent systematic review revealed a significant increase in illness risk in people living farther away from their water source (Wang & Hunter 2010), whereas shortening the one-way walk time to water sources by 15 min is associated with a 41% average relative reduction in diarrhoea prevalence, improved anthropometric indicators of child nutritional status and a 11% reduction in under-five child mortality (Pickering & Davis 2012).

While quality, quantity and access are fundamental to the MDG water target, however, they are only indirectly assessed by current methods for monitoring progress toward such target. The simple explanation for this is that monitoring these conditions on a global or even national scale is difficult, costly and beyond the capacity of existing monitoring systems.

When the time came to actually monitor progress towards the MDG water target, the Inter-Agency and Expert Group on MDG Indicators decided to rely on an existing system of reporting on water and sanitation that was never designed to capture the core components of the MDG water target (United Nations 2003). The WHO/UNICEF Joint Monitoring Committee on Water and Sanitation (JMP) was organised in the 1980s, among other things, for the purpose of monitoring sector progress towards internationally established goals on access to water supply and sanitation. Its data come from national household-level surveys, including the Demographic and Health Survey and the Multiple Indicator Cluster Survey, as well as local census data. Using such surveys to collect the data, however, requires the JMP to rely on indicators for water coverage that minimally trained survey administrators could identify and count; it does not have the tools or budget to measure water quality directly, or clear methods for assessing quantity and access. As a result, the JMP reports not on quality, quantity and access, but uses a proxy for these that is based on the type of supply the householder reports as its primary source of drinking water (WHO/UNICEF 2012). For this purpose, it counts the source as ‘improved’ if it consists of piped water, public taps, boreholes, protected wells, protected springs or rainwater; unimproved sources include any other supply, including vendor-provided water, bottled water (in most cases), tanker trucks, unprotected wells and springs or surface water.

The JMP has been clear about the shortcomings of relying on the binary improved/unimproved typology to capture essential aspects of ‘sustainable access to safe drinking water’. Its own field studies in six countries to explore options for assessing water quality directly found that except for some centrally managed piped water supplies, the so-called ‘improved sources’ were often microbiologically and chemically contaminated and that the level of faecal contamination was significantly worse at the household level (WHO/UNICEF 2010). One UN announcement about meeting the MDG water target made this clear: ‘Water quality surveys showed that many improved drinking water sources such as piped supplies, boreholes and protected wells do not conform to WHO guidelines. On average, half of all protected dug wells may be contaminated, along with a third of protected springs and boreholes’ (United Nations 2011). Even the 2012 JMP report acknowledges that ‘[t]he safety and reliability of drinking water supplies and the sustainability of both water supply sources and sanitation facilities are not addressed by the current set of indicators used to track progress’ and that ‘it is likely that the number of people using safe water supplies has been over-estimated.’ (WHO/UNICEF 2012).

Moreover, although the JMP collects data on time spent collecting water to provide information on access (and thus, indirectly, quantity), this is not factored into the improved/unimproved characterisation of water supplies that is the sole basis for scoring towards the MDG water target. A closer review of the JMP report shows that only a quarter of householders have water that is ‘piped on premises’ (WHO/UNICEF 2012). The other three-quarters travel once or more daily to collect their water, travelling a mean time of approximately 30 min round trip – a distance that makes it unlikely that they are procuring enough water for personal hygiene much less other productive uses such as irrigating gardens that could be used to improve nutrition (White et al. 1972). Moreover, in 71% of all households without water on the premises, women or girls are mainly responsible for water collection, taking time away from caring for children (also predominantly done by them) or attending school and thus undermining other important MDG targets. Except for those who have achieved water that is ‘piped on premises’, the claim that the MDG water target has been met says little about the extent to which we have actually improved ‘sustainable access’ (WHO/UNICEF 2012).

Announcements about meeting the MDG water target did acknowledge other sobering facts: that there are 780 million people still un-served even by ‘improved’ water sources; that rural, poor and sub-Saharan Africa have far lower rates of coverage; and that most of these same people are among the 2.5 billion who lack improved sanitation (WHO/UNICEF 2012).

Joint Monitoring Programme monitoring of drinking water performs an essential role, and the biannual reports demonstrate clear progress. Its reports actually provide important information that would be obscured by the global nature of the MDG targets. This includes disaggregating data to show national and regional progress; highlighting of urban/rural disparities; presenting the ‘ladder’ to show progress towards household piped water supplies; and developing a new alternative index that does not penalise countries that started from a lower level of coverage or that have large population growth. It is also piloting new technologies that actually measure water quality in the field and is exploring options for assessing quantity, access and sustainability (WHO/UNICEF 2012). These developments are likely to lead to better metrics for the targets that succeed the MDGs.

In the meantime, let us hope that the announcement that the water target has been met does not shift resources to other priorities, thereby putting at risk continued progress on critical health goals that depend on ensuring sustainable access to safe drinking water.

Wang X & Hunter PR (2010) A systematic review and meta-analysis of the association between self-reported diarrheal disease and distance from home to water source. American Journal of Tropical Medicine and Hygiene83, 582–584.

5Batsirai Majuru, Marc Suhrcke, Paul Hunter, How Do Households Respond to Unreliable Water Supplies? A Systematic Review, International Journal of Environmental Research and Public Health, 2016, 13, 12, 1222CrossRef